document the format of DSA signature

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/23762)

diff --git a/doc/man7/EVP_SIGNATURE-DSA.pod b/doc/man7/EVP_SIGNATURE-DSA.pod
index 6a2def1c0be8fbb0a40bd540daf4079335db18c4..2c0f0073a4fae4550a170e179d8de175b4576dd0 100644 (file)
--- a/doc/man7/EVP_SIGNATURE-DSA.pod
+++ b/doc/man7/EVP_SIGNATURE-DSA.pod
@@ -7,7 +7,9 @@ EVP_SIGNATURE-DSA
 
 =head1 DESCRIPTION
 
-Support for computing DSA signatures.
+Support for computing DSA signatures. The signature produced with
+L<EVP_PKEY_sign(3)> is DER encoded ASN.1 in the form described in
+RFC 3279, section 2.2.2.
 See L<EVP_PKEY-DSA(7)> for information related to DSA keys.
 
 As part of FIPS 140-3 DSA is not longer FIPS approved for key generation and